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Bacillus thuringiensis (Bt) are entomopathogenic bacteria that produce different kinds of insecticidal proteins. However, studies on Bt exopolysaccharides are lacking. Here, we aimed to explore the characteristics and insecticidal synergism of EPS-2, an exopolysaccharide from Bt strain 4D19. The molecular weight of EPS-2 was 58.0 kDa, which consisted of mannose (44.2%), GlcN (35.5%), D-GalN (8.0%), glucose (5.5%), arabinose (5.1%), galactose (0.9%), Man-UA (0.3%) and Glc-UA (0.2%). The toxicity of insecticidal proteins against Plutella xylostella was increased by adding EPS-2. EPS-2 bound to Cry1Ac protoxin and promoted the binding of Cry1Ac protoxin to the gut membrane of P. xylostella, but did not bind to activated toxins. These results suggested that EPS-2 may bind to the protoxin C-terminal region to enhance insecticidal activity. Our findings indicated that Bt strains produce exopolysaccharide to enhance the toxicity of insecticidal crystal proteins, which could be applied in biopesticide research and product development.
Meiling Wang; Lili Geng; Bai Xue; Zeyu Wang; Wenyue Xu; Changlong Shu; Jie Zhang. Structure characteristics and function of a novel extracellular polysaccharide from Bacillus thuringiensis strain 4D19. International Journal of Biological Macromolecules 2021, 1 .
AMA StyleMeiling Wang, Lili Geng, Bai Xue, Zeyu Wang, Wenyue Xu, Changlong Shu, Jie Zhang. Structure characteristics and function of a novel extracellular polysaccharide from Bacillus thuringiensis strain 4D19. International Journal of Biological Macromolecules. 2021; ():1.
Chicago/Turabian StyleMeiling Wang; Lili Geng; Bai Xue; Zeyu Wang; Wenyue Xu; Changlong Shu; Jie Zhang. 2021. "Structure characteristics and function of a novel extracellular polysaccharide from Bacillus thuringiensis strain 4D19." International Journal of Biological Macromolecules , no. : 1.
Vip3Aa was first identified as a protein secreted during the vegetative growth phase of Bacillus thuringiensis (Bt) bacteria and which shows high insecticidal toxicity against lepidopteran insect pests (Estruch et al., 1996). Bt strains formulated as bio‐insecticides only had low amounts of Vip3Aa secreted to the medium. Here, we report that Vip3Aa proteins produced by three different Bt strains, including an industrial strain, were indeed not secreted to the culture solution when grown in sporulation medium, but were retained in the mother cell compartment. In order to further investigate the Vip3Aa secretion and location, we grew the strains in rich medium. We found that in rich medium, a fraction of Vip3Aa was secreted, suggesting that Vip3Aa secretion is nutrient‐dependent. Regardless of the growth conditions, we found that Vip3Aa retained in cell pellets exhibited high toxicity against Spodoptera frugiperda larvae. Hence, we speculate that the accumulation of Vip3Aa protein in the mother cell compartment under sporulation conditions could still be used as an efficient strategy for industrial production in commercial Bt strains.
Zeyu Wang; Chunxia Gan; Jian Wang; Alejandra Bravo; Mario Soberón; Qing Yang; Jie Zhang. Nutrient conditions determine the localization of Bacillus thuringiensis Vip3Aa protein in the mother cell compartment. Microbial Biotechnology 2020, 14, 551 -560.
AMA StyleZeyu Wang, Chunxia Gan, Jian Wang, Alejandra Bravo, Mario Soberón, Qing Yang, Jie Zhang. Nutrient conditions determine the localization of Bacillus thuringiensis Vip3Aa protein in the mother cell compartment. Microbial Biotechnology. 2020; 14 (2):551-560.
Chicago/Turabian StyleZeyu Wang; Chunxia Gan; Jian Wang; Alejandra Bravo; Mario Soberón; Qing Yang; Jie Zhang. 2020. "Nutrient conditions determine the localization of Bacillus thuringiensis Vip3Aa protein in the mother cell compartment." Microbial Biotechnology 14, no. 2: 551-560.
Scarabaeoidea and Chrysomeloidea insects are agriculture-destructive coleopteran pests. Few effective Bacillus thuringiensis (Bt) insecticidal proteins against these species have been described. Bt isolate BtSU4 was found to be active against coleopteran insects. Genome sequencing revealed two new cry8 genes in BtSU4, designated as cry8Ha1 and cry8Ia1. Both genes expressed a 135 kDa protoxin forming irregular shape crystals. Bioassays performed with Cry8Ha1 protoxin showed that it was toxic to both larvae and adult stages of Holotrichia parallela, also to Holotrichia oblita adults and to Anoplophora glabripennis larvae, but was not toxic to larval stages of H. oblita or Colaphellus bowringi. The Cry8Ia1 protoxin only showed toxicity against H. parallela larvae. After activation with chymotrypsin, the Cry8Ha1 activated toxin lost its insecticidal activity against H. oblita adults and reduced its activity on H. parallela adults, but gained toxicity against C. bowringi larvae, a Chrysomeloidea insect pest that feeds on crucifer crops. The chymotrypsin activated Cry8Ia1 toxin did not show toxicity to any one of these insects. These data show that Cry8Ha1 and Cry8Ia1 protoxin and activated toxin proteins have differential toxicity to diverse coleopteran species, and that protoxin is a more robust protein for the control of coleopteran insects.
Changlong Shu; Guixin Yan; Shizhi Huang; Yongxin Geng; Mario Soberón; Alejandra Bravo; Lili Geng; Jie Zhang. Characterization of Two Novel Bacillus thuringiensis Cry8 Toxins Reveal Differential Specificity of Protoxins or Activated Toxins against Chrysomeloidea Coleopteran Superfamily. Toxins 2020, 12, 642 .
AMA StyleChanglong Shu, Guixin Yan, Shizhi Huang, Yongxin Geng, Mario Soberón, Alejandra Bravo, Lili Geng, Jie Zhang. Characterization of Two Novel Bacillus thuringiensis Cry8 Toxins Reveal Differential Specificity of Protoxins or Activated Toxins against Chrysomeloidea Coleopteran Superfamily. Toxins. 2020; 12 (10):642.
Chicago/Turabian StyleChanglong Shu; Guixin Yan; Shizhi Huang; Yongxin Geng; Mario Soberón; Alejandra Bravo; Lili Geng; Jie Zhang. 2020. "Characterization of Two Novel Bacillus thuringiensis Cry8 Toxins Reveal Differential Specificity of Protoxins or Activated Toxins against Chrysomeloidea Coleopteran Superfamily." Toxins 12, no. 10: 642.
Sclerotiniose, caused by Sclerotinia sclerotiorum (Lib.) deBary, is a destructive disease of Brassica campestris L. Injuries caused by insect pests, such as Plutella xylostella (L.), increase the occurrence of this disease. One hundred and sixty-one Bacillus thuringiensis strains from the Bacillus Genetic Stock Center were screened to identify strains that might protect B. campestris from both plant diseases and insect pests in this study. Challenge-inoculation assays showed seventeen B. thuringiensis strains effectively suppressed S. sclerotiorum growth by inducing systemic resistance in B. campestris, and six of these strains exhibited high insecticidal activity against P. xylostella. In addition, B. thuringiensis elicited a strong hypersensitive response in B. campestris leaves and triggered systemic signals that were transferred from treated roots and leaves to untreated leaves. Quantitative real-time PCR and transcriptome sequencing showed genes involved in salicylic acid, ethylene, and jasmonic acid signaling and in brassinosteroid synthesis pathways were upregulated. The phenotypic and genotypic diversity of B. thuringiensis makes it an effective biocontrol agent for simultaneously protecting B. campestris from sclerotiniose and P. xylostella.
Meiling Wang; Lili Geng; Xiaoxiao Sun; Changlong Shu; Fuping Song; Jie Zhang. Screening of Bacillus thuringiensis strains to identify new potential biocontrol agents against Sclerotinia sclerotiorum and Plutella xylostella in Brassica campestris L. Biological Control 2020, 145, 104262 .
AMA StyleMeiling Wang, Lili Geng, Xiaoxiao Sun, Changlong Shu, Fuping Song, Jie Zhang. Screening of Bacillus thuringiensis strains to identify new potential biocontrol agents against Sclerotinia sclerotiorum and Plutella xylostella in Brassica campestris L. Biological Control. 2020; 145 ():104262.
Chicago/Turabian StyleMeiling Wang; Lili Geng; Xiaoxiao Sun; Changlong Shu; Fuping Song; Jie Zhang. 2020. "Screening of Bacillus thuringiensis strains to identify new potential biocontrol agents against Sclerotinia sclerotiorum and Plutella xylostella in Brassica campestris L." Biological Control 145, no. : 104262.
The estrogen-like mycotoxin zearalenone (ZEN) is one of the most widely distributed contaminants especially in maize and its commodities, such as corn oil. ZEN degrading enzymes possess the potential for counteracting the negative effect of ZEN and its associated high safety risk in corn oil. Herein, we targeted enhancing the secretion of ZEN degrading enzyme by Pichia pastoris through constructing an expression plasmid containing three optimized expression cassettes of zlhy-6 codon and signal peptides. Further, we explored various parameters of enzymatic detoxification in neutralized oil and analyzed tocopherols and sterols losses in the corn oil. In addition, the distribution of degraded products was demonstrated as well by Agilent 6510 Quadrupole Time-of-Flight mass spectrometry. P. pastoris GSZ with the glucoamylase signal was observed with the highest ZLHY-6 secretion yield of 0.39 mg/mL. During the refining of corn oil, ZEN in the crude oil was reduced from 1257.3 to 13 µg/kg (3.69% residual) after neutralization and enzymatic detoxification. Compared with the neutralized oil, no significant difference in the total tocopherols and sterols contents was detected after enzymatic detoxification. Finally, the degraded products were found to be entirely eliminated by washing. This study presents an enzymatic strategy for efficient and safe ZEN removal with relatively low nutrient loss, which provides an important basis for further application of enzymatic ZEN elimination in the industrial process of corn oil production.
Xiaojiao Chang; Hujun Liu; Jing Sun; Jun Wang; Chengcheng Zhao; Wan Zhang; Jie Zhang; Changpo Sun. Zearalenone Removal from Corn Oil by an Enzymatic Strategy. Toxins 2020, 12, 117 .
AMA StyleXiaojiao Chang, Hujun Liu, Jing Sun, Jun Wang, Chengcheng Zhao, Wan Zhang, Jie Zhang, Changpo Sun. Zearalenone Removal from Corn Oil by an Enzymatic Strategy. Toxins. 2020; 12 (2):117.
Chicago/Turabian StyleXiaojiao Chang; Hujun Liu; Jing Sun; Jun Wang; Chengcheng Zhao; Wan Zhang; Jie Zhang; Changpo Sun. 2020. "Zearalenone Removal from Corn Oil by an Enzymatic Strategy." Toxins 12, no. 2: 117.
Bacillus thuringiensis Cry1Ai belongs to three-domain Cry toxins and only shows growth inhibition effects against the agricultural pest Helicoverpa armigera, although it exhibits high toxicity against the non-target insect Bombyx mori. In previous studies, loop2 and loop3 on domain II from Cry1Ah were found to be related to binding and high toxicity against H. armigera. However, toxicity for B. mori of Cry1Ai-h-loop2, obtained by replacing loop 2 from Cry1Ah into Cry1Ai, was not modified. In this study, to further characterize the role of loop2 and loop3 in Cry1Ai, all of the amino acids in these two loops were substituted with the same amount of alanine residues. The Cry1Ai-loop3 mutant exhibited significantly lower toxicity against B. mori, but the toxicity of the loop2 mutant was not significantly changed. Furthermore, the double-exchange mutant Cry1Ai-h-loop2&3, replacing loop2 and loop3 from Cry1Ah into Cry1Ai, showed decreased toxicity against B. mori related to Cry1Ai. In addition, we found that the binding affinity of Cry1Ai-h-loop2&3 with brush border membrane vesicles (BBMVs) from the midgut of B. mori was lower than that of Cry1Ai, which correlates with the reduced toxicity.
Yuxiao Liu; Zishan Zhou; Zeyu Wang; Boxiong Zhong; Changlong Shu; Jie Zhang. Replacement of loop2 and 3 of Cry1Ai in domain II affects specificity to the economically important insect Bombyx mori. Journal of Invertebrate Pathology 2019, 169, 107296 .
AMA StyleYuxiao Liu, Zishan Zhou, Zeyu Wang, Boxiong Zhong, Changlong Shu, Jie Zhang. Replacement of loop2 and 3 of Cry1Ai in domain II affects specificity to the economically important insect Bombyx mori. Journal of Invertebrate Pathology. 2019; 169 ():107296.
Chicago/Turabian StyleYuxiao Liu; Zishan Zhou; Zeyu Wang; Boxiong Zhong; Changlong Shu; Jie Zhang. 2019. "Replacement of loop2 and 3 of Cry1Ai in domain II affects specificity to the economically important insect Bombyx mori." Journal of Invertebrate Pathology 169, no. : 107296.
Bacillus thuringiensis is a well-known entomopathogenic bacterium that produces vegetative insecticidal proteins (Vips, including Vip1, Vip2, Vip3, and Vip4) during the vegetative phase. Here, we purified Vip1 and Vip2 from B. thuringiensis and characterized the insecticidal effects of these protoxins. Bioassay results showed that a 1:1 mixture of Vip1Ad and Vip2Ag, purified by ion-affinity chromatography independently, exhibited insecticidal activity against Holotrichia parallela larvae, with a 50% lethal concentration value of 2.33 μg/g soil. The brush border membrane (BBM) in the midgut of H. parallela larvae was destroyed after feeding the Vip1Ad and Vip2Ag mixture. Vacuolization of the cytoplasm and slight destruction of BBM were detected with Vip2Ag alone, but not with Vip1Ad alone. Notably, Vip1Ad bound to BBM vesicles (BBMVs) strongly, whereas Vip2Ag showed weak binding; however, binding of Vip2Ag to BBMV was increased when Vip1Ad was added. Ligand blotting showed that Vip2Ag did not bind to Vip1Ad but bound to Vip1Ad-t (Vip1Ad was activated by trypsin), suggesting the activation of Vip1Ad was important for their binary toxicity. Thus, our findings suggested that Vip1Ad may facilitate the binding of Vip2Ag to BBMVs, providing a basis for studies of the insecticidal mechanisms of Vip1Ad and Vip2Ag.
Jianxun Geng; Jian Jiang; Changlong Shu; Zeyu Wang; Fuping Song; Lili Geng; Jiangyan Duan; Jie Zhang. Bacillus thuringiensis Vip1 Functions as a Receptor of Vip2 Toxin for Binary Insecticidal Activity against Holotrichia parallela. Toxins 2019, 11, 440 .
AMA StyleJianxun Geng, Jian Jiang, Changlong Shu, Zeyu Wang, Fuping Song, Lili Geng, Jiangyan Duan, Jie Zhang. Bacillus thuringiensis Vip1 Functions as a Receptor of Vip2 Toxin for Binary Insecticidal Activity against Holotrichia parallela. Toxins. 2019; 11 (8):440.
Chicago/Turabian StyleJianxun Geng; Jian Jiang; Changlong Shu; Zeyu Wang; Fuping Song; Lili Geng; Jiangyan Duan; Jie Zhang. 2019. "Bacillus thuringiensis Vip1 Functions as a Receptor of Vip2 Toxin for Binary Insecticidal Activity against Holotrichia parallela." Toxins 11, no. 8: 440.
Coleoptera, the order of insects commonly referred to as beetles, are able to survive in various environments, and thus, comprise the largest order in the animal kingdom. Coleopterans mainly include coprophagous and phytophagous lineages, and many species of the latter lineage are serious pests. In addition to traditional chemical methods, biocontrol measures using various bacterial insecticidal proteins have also gradually been developed to control these insect pests. In this review, we summarized the possible coleopteran‐pest‐specific bacteria and insecticidal proteins that have been reported in the literature thus far and have provided a comprehensive overview and long‐term guidance for the control of coleopteran pests in the future.
Kui Wang; Changlong Shu; Jie Zhang. Effective bacterial insecticidal proteins against coleopteran pests: A review. Archives of Insect Biochemistry and Physiology 2019, 102, e21558 .
AMA StyleKui Wang, Changlong Shu, Jie Zhang. Effective bacterial insecticidal proteins against coleopteran pests: A review. Archives of Insect Biochemistry and Physiology. 2019; 102 (3):e21558.
Chicago/Turabian StyleKui Wang; Changlong Shu; Jie Zhang. 2019. "Effective bacterial insecticidal proteins against coleopteran pests: A review." Archives of Insect Biochemistry and Physiology 102, no. 3: e21558.
Cry1Ai-h-loop 2 is a mutant of Cry1Ai constructed by exchanging loop 2 from Cry1Ah protein and shows insecticidal activity against Helicoverpa armigera. The toxicity of Cry1Ai-h-loop 2, in contrast to the very low toxicity of Cry1Ai, is closely associated with the eleven residues in the loop 2 region. To characterize the key sites of loop 2 in Cry1Ai-h-loop 2, alanine-substituted mutants were generated. The toxicity of these mutants against H. armigera indicated that dual-mutant on Gly373 and Asn375 caused a significant decrease in toxic activity. ELISA binding and competition binding assays demonstrated that the reduction of toxicity in the mutant of interest was correlated with decreased binding affinity.
Yu-Xiao Liu; Zi-Shan Zhou; Ge-Mei Liang; Fu-Ping Song; Jie Zhang. Alanine-substituted mutant on Gly373 and Asn375 of Cry1Ai-h-loop 2 causes reduction in both toxicity and binding against Helicoverpa armigera. Journal of Integrative Agriculture 2019, 18, 1064 -1071.
AMA StyleYu-Xiao Liu, Zi-Shan Zhou, Ge-Mei Liang, Fu-Ping Song, Jie Zhang. Alanine-substituted mutant on Gly373 and Asn375 of Cry1Ai-h-loop 2 causes reduction in both toxicity and binding against Helicoverpa armigera. Journal of Integrative Agriculture. 2019; 18 (5):1064-1071.
Chicago/Turabian StyleYu-Xiao Liu; Zi-Shan Zhou; Ge-Mei Liang; Fu-Ping Song; Jie Zhang. 2019. "Alanine-substituted mutant on Gly373 and Asn375 of Cry1Ai-h-loop 2 causes reduction in both toxicity and binding against Helicoverpa armigera." Journal of Integrative Agriculture 18, no. 5: 1064-1071.